The present invention relates to the field of copiers and scanners, and is particularly useful for digital electro photographic machines.
When scanning a document in a parked head scanner, contamination on the scanning glass slit can result in undesirable effects on the copies produced. Such contamination can result from paper dust, toner, etc. Prior art has used the original itself to wipe the scanning glass clean as it is transported across the scanning glass slit. However the weight of the paper itself is not always sufficient to clean the glass. Guides have been employed to apply pressure to the originals as they pass over the scanning glass slit, however to avoid jamming the lightweight paper, these guides have had clearance between the guide and the scanning glass slit. Because of this, lightweight paper is not effectively cleaning the glass.
A floating guide is desired which could apply pressure to a full range of papers, including lightweight papers, without jamming the lightweight papers.
There is a passively energized floating guide in a parked head scanner, which enables the original paper to clean the scanning glass slit. The scanning glass slit has an end one and an end two which are longitudinally opposing ends and wherein the paper crosses the scanning glass slit latitudinally moving from the entrance side to the exit side. The passively energized floating guide comprises an end plate one, an end plate two, and a wiper bar. The end plate one has a slot one, and is mounted to the scanner at the scanning glass slit end one. The end plate two has a slot two, and is mounted to the scanner at the scanning glass slit end two.
The wiper bar has a wiper bar end one and an opposing wiper bar end two, and has a pivot point. The wiper bar end one is pivotally attached at the pivot point to the end plate one through slot one, and the wiper bar end two is pivotally attached at the pivot point to the end plate two through slot two such that when at rest, the wiper bar rests on the scanning glass slit. The wiper bar weight, shape, and pivot point are chosen such that as paper passes over the scanning glass slit, the force of the paper causes the wiper bar to rotate slightly allowing paper to pass between the wiper bar and the scanning glass slit, and passively energizes the wiper bar such that it applies pressure on the paper.